In the past, keypads on cellular radiotelephones device have comprised a multi-layered structure having a large part count that is relatively thick, thus limiting the thinness of the devices in which the keypad is integrated. Typical keypads include a user interface forming user accessible key caps, which are sometimes interconnected by a web. The key caps are each aligned over a corresponding switch-dome mounted on a carrier made of Mylar or some other carrier material. The carrier and dome assembly is disposed on a switch contact circuitry layer.
To provide keypad lighting, it is known to dispose a luminescent layer between the dome carrier and the key caps. The luminescent layer however includes cutouts through which plunger portions of the key caps may contact the domes to actuate switches on the circuit layer. This configuration lacks luminescence directly below or behind the key caps where it is desired most. Instead, the key caps are lighted indirectly by dispersed light, some of which emanates from circumferential areas surrounding the keys.
The various aspects, features and advantages of the disclosure will become more fully apparent to those having ordinary skill in the art upon careful consideration of the following Detailed Description thereof with the accompanying drawings described below.